Bulk grown (from-the-melt) semiconductor single crystals are basic ingredients for modern electronic and sensor devices. The directional solidification of single crystals is a difficult process due to various problems, one of which is the difficulty of precisely controlling the solid/liquid interface shape. This lack of control is due to temperature differential between the "adiabatic zone" of the furnace and the solidifying material. The cause of this is the difference in thermal conductivity between the liquid and solid phases and the inability to create a truly adiabatic zone in which no radial heat transfer occurs. Radial heat transfer produces a non-linear interface shape and potentially an increase in the convection effects. A better matched or controlled temperature profile between furnace and the material to be solidified will result in improved interface shape control.